Motor ignition control



Nov. 13, 1945.

F. E. WOOD MOTOR IGNITION CONTROL Filed May 27, 1945 Patented Nov. 13, 1945 UNITED STATES PATENT 'OFFECE MOTOR IGNITION CONTROL Fremont E. Wood, Gabbs Valley, Nev.

Application May 27, 1943, Serial No. 488,731

1 Claim.

This irivention relates to a control for motors, particularly internal combustion engines, land is designed automatically to stop or cut out the ignition in the event of overheating from various causes and particularly from the lack of water, the invention being applicable in connection with propelling engines of automobiles, trucks, tractors, aircraft, vessels, stationary engines, and generally,

It is particularly aimed to incorporate into the ignition circuit, 'by shunt means, a switch mechanism which automatically will open through the condition of overheating and which preferably at the same time visually will indicate such a condition.

The more specific objects and advantages will become apparent from a consideration of the description following taken in connection with accompanying drawing illustrating an operative embodiment.

In said drawing:

Figure 1 is a View illustrating the invention, particularly in diagram, but in part being vertical section; and

Figure 2 is a cross-section taken on the line 2-2 of Figure 1.

Referring specifically to said drawing, wherein like reference characters designate like or similar parts, a fragment of an internal combustion engine is conventionally shown at I the fragment being specically the cylinder head. It is to be understood that such a showing or suggestion is to be taken as conventional since the engine or motor may be of the type employed for any desired purpose. One of the spark plugs is shown at I I, the same being of conventiona1type, and through a conductor I2 being operatively connected to a conventional distributor I3 with which, through conductors I4 and I5, the conventional ignition coil I6 is operatively associated. It will be clear of course that all spark plugs of the internal combustion engine are operatively connected to the distributor I3 and ignition coil I6, but that they have been omitted for the sake of clarity.

A conductor I1 leads from the ignition coil and has branches Ila and IIb connected to a bi-metallic thermostatic switch generally designated I8. Such branch Ilb connects directly with the starting, lighting, and ignition battery I9 of the vehicle, and included therein is the conventional key-operable ignition switch 20. It will be clear that one pole of the battery I9 as usual is grounded at 2| to the frame of the vehicle and the motor or engine part I0.

Preferably connected across the branch conductors Ila and I'lb is a conductor 22 which includes a condenser at 23.

More specically, the bi-metallic thermostatic switch I8 preferably includes a plug at 24 which is detachably screw-threaded at 25 in a hole in the cylinder head I0. Plug 24 carries a closed tube 26 of brass or other metal which will expand and particularly elongate upon being heated. It will be noted that the inner end of the tube or shell 26 is free for this purpose. Such tube or shell is disposed directly in the space or water jacket 2l of the cylinder head I0 in order to be in contact with and subject to the temperature of the water in such jacket.

Within the shell 26 a pin 28 is anchored at one end and has a pair of fingers 30 of any suitable thermally inert metal fastened thereto. The other ends of such ngers 30 are fastened to a stud 3| carried by an adjusting screw 32, screwthreaded into plug 24 as at 33.

A pair of normally engaged contact points 34 are carried by but insulated from the lingers 30, and the branch conductor Ila extends through the plug 24 and is connected to one of them, while the branch conductor I'Ib extends through the plug and is connected to the other of them. Such portions of the conductors Ila and IIb which extend through the plug 24 and into the tube or shell 26 are covered with insulation as at 35 and 36 respectively.

A visual signal inthe form of a lamp 31, for instance, is shunted into the ignition circuit as by connecting conductors 38 and 39 to the conductors Ila and I'Ib. Preferably the lamp 31 is disposed behind a translucent or transparent sign 40, or adjacent to an equivalent sign, which will indicate the fact that the motor has overheated, when the lamp is illuminated, and which sign preferably is disposed on the dash or instrument board of the vehicle equipped with the motor. It is clear of course that in lieu of a visual signal, an audible signal or both may be used.

In the normal operation of the motor, with switch 20 closed, the contacts 34 also will be closed and they will remain closed` during a safe range of temperatures for operation of the motor. In the event of overheating, that is, heating above a predetermined desired or safe temperature the shell or tube 26 will inwardly elongate, thereby straightening the ngers 30 and separating the contact points 34, thereby permitting electric current to flow in the shunt conductors 38-39, illuminating the signal 3l. This action not only indicates to the driver or party in control of the motor that the motor is overheated, but it also introduces so much resistance into the circuit that the ignition coil will not function with the amount of current owing through it. When the condition is remedied, and the parts are sufficiently cooled, the thermostatic switch automatically will close through the re-engagement of the contact points 34, the lamp 31 becoming extinct due to the resistance and to the fact that the current will iiow through the contact points which will oier less resistance.

I prefer to use a type of thermostatic switch like that disclosed, since it will be accurate in operation, although changes may be made within the spirit and scope of the invention as dened by appended claim.

Although I have disclosed the thermostatic switch as located within the water jacket and subject to contact with the water therein, this is to be taken as by way of example only, since the thermostatic switch may be located or mounted at any advantageous point, to be subject to the heat developed by the engine.

I claim as my invention:

In the ignition circuit of an internal combustion engine including an ignition coil, a thermostatic means subject to the temperature of the coolant of the engine, a switch in said circuit normally closed below a predetermined temperature, said switch being connected to said thermostatic means for opening through expansion of the thermostatic means, and signal means shunted in said circuit for actuation through opening of said switch for the dual purpose of signaling and imposing resistance to render the ignition coil of the circuit ineiective at and above said predetermined temperature.

FREMONT E. WOOD. 

